A variable temperature microfluidic auxiliary printing device and method for FDM 3D printing

Abstract

The present invention provides a variable temperature microfluidic auxiliary printing device and method for FDM 3D printing, belonging to the technical field of 3D printing; solving the problems of diversity, temperature control and printing efficiency existing in the traditional FDM 3D printing technology; comprising a microfluidic auxiliary printing device, the microfluidic auxiliary printing device comprises a shell, a plurality of push tubes are arranged on the top of the shell, a plurality of nozzles with a static mixing structure are arranged on the bottom of the shell, a microfluidic device is arranged inside the shell, the microfluidic device comprises a heater, a microfluidic pipeline, a coolant pipeline and a temperature sensor, the heater is arranged in a circle along the inner axis of the shell, the microfluidic pipeline surrounds the heater, the coolant pipeline surrounds the microfluidic pipeline, each microfluidic pipeline is equipped with a temperature controller, the feed inlet of the microfluidic pipeline is connected to the feed outlet of the push tube, and the feed outlets of the plurality of microfluidic pipelines meet before entering the nozzle; the present invention is applied to 3D printing.

Description

Technical Field

[0001] The present invention provides a variable temperature microfluidic auxiliary printing device and method for FDM 3D printing, belonging to the technical field of 3D printing. Background Art

[0002] 3D printing technology (also known as additive manufacturing, rapid prototyping or additive manufacturing) is a manufacturing method that builds objects by stacking materials layer by layer. Unlike traditional subtractive manufacturing (such as cutting, carving, etc.), 3D printing technology allows designers to create objects in a more free and flexible way by adding materials layer by layer. The history of FDM3D printing technology can be traced back to the 1980s. It is one of the earliest and most mature 3D printing technologies. Internationally, 3D printing technology has been constantly innovating and developing. More and more research is devoted to improving the accuracy, speed and diversity of 3D printing. As an emerging technology, microfluidic technology has achieved remarkable application results in the fields of biomedicine, chemical analysis and drug research and development. However, in the field of 3D printing, the application of microfluidic technology is still in its infancy. With the rapid development and technological innovation of the manufacturing industry, 3D printing technology has become one of the key areas of national strategic support. Various 3D printing technologies continue to emerge, bringing new opportunities and challenges to all links of the industrial chain. With the continuous maturity of 3D printing technology, the demand for multi-material, multi-functional and high-efficiency printing is also increasing.

[0003] With the continuous development of 3D printing technology, more and more manufacturing fields have begun to adopt this advanced manufacturing method. However, traditional FDM (fused deposition manufacturing) 3D printing technology has some limitations, especially when it comes to achieving diversified printed objects. Existing FDM 3D printing methods can usually only use fixed materials and process parameters, which limits the diversity and complexity of printed objects. In addition, for some specific applications, such as tissue engineering, medical device manufacturing, and energy device manufacturing, the printing materials are required to have different properties and characteristics at different temperatures. However, in traditional FDM3D printing, the ability to control the temperature of the material is limited and often cannot meet the needs of these specific applications.

[0004] In summary, in order to overcome the limitations of traditional FDM 3D printing technology and meet the needs of different application fields, the present invention aims to provide a variable temperature microfluidic assisted printing device and method that can realize real-time dynamic temperature, flow and mixing control, so as to achieve higher printing diversity, accuracy and adaptability. Summary of the invention

[0005] In order to solve the problems of diversity, temperature control and printing efficiency in traditional FDM 3D printing technology, the present invention proposes a variable temperature microfluidic auxiliary printing device and method for FDM 3D printing.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a variable temperature microfluidic auxiliary printing device for FDM3D printing, including a microfluidic auxiliary printing device, the microfluidic auxiliary printing device includes a shell, a plurality of push tubes are arranged on the top of the shell, a plurality of nozzles with a static mixing structure are arranged on the bottom of the shell, a microfluidic device is arranged inside the shell, the microfluidic device includes a heater, a microfluidic pipeline, a coolant pipeline and a temperature sensor, the heater is arranged in a circle along the inner axis of the shell, the microfluidic pipeline surrounds the heater, the coolant pipeline surrounds the microfluidic pipeline, each microfluidic pipeline is equipped with a temperature sensor, the coolant pipeline is connected to an external cooling system, the feed inlet of the microfluidic pipeline is connected to the feed outlet of the push tube, and the feed outlets of the plurality of microfluidic pipelines meet before entering the nozzle;

[0007] The controller of the microfluidic device is connected to the control end of the heater, the temperature sensor, and the control end of the external cooling system through wires.

[0008] The nozzle includes a nozzle, a mixer, a through hole and a connecting joint. The nozzle is conical, and a plurality of circular grooves distributed along the axial direction and surrounding the main axis are arranged on the inner wall of the nozzle. The circular grooves are used to fix the position of the mixer. The mixers of each layer are interconnected. A connecting joint is arranged on the top of the nozzle, and the nozzle is connected to the microfluidic pipeline through the connecting joint. The mixer is arranged in the nozzle and is a staggered arrangement structure of special-shaped plates. The through hole is arranged in the mixer, and is used to divide, reorganize and mix the fluid when passing through, so that the fluid produces a rotational motion.

[0009] A rotating structure is arranged outside the shell, and the rotating structure includes two metal rods with driving pinions and a microfluidic gear track groove arranged outside the shell, and an external large gear is arranged in the microfluidic gear track groove, and the external large gear is meshed with the driving pinions on the two metal rods, and the driving end of the driving pinion is connected to the controller of the microfluidic device through a wire.

[0010] The bottom of the shell is provided with cross-arranged interfaces, each interface is equipped with a nozzle with a static mixing structure, and the nozzle is located on the rotation plane of the microfluidic auxiliary printing device.

[0011] The external cooling system is composed of a plurality of coolant tanks and a heat dissipation device.

[0012] The temperature sensor is arranged at a distance of 2-3 mm from the microfluidic channel.

[0013] The push tube is made of stainless steel and is equipped with an elastic support structure connecting gears. The gears are arranged on the inner wall of the push tube through a connecting rod and are used to push the wire. The elastic support structure is arranged on the inner wall of the push tube and is used to make the push tube adaptively adjust the thickness of the push wire and stably fix the wire inside the push tube. An aerogel gasket is installed at the connection between the lower end of the push tube and the microfluidic assisted printing device, and the upper end of the push tube is connected to the extruder through the wire.

[0014] A variable temperature microfluidic assisted printing method for FDM 3D printing, using a variable temperature microfluidic assisted printing device for FDM 3D printing, comprising the following steps:

[0015] The variable temperature microfluidic auxiliary printing device is installed on the existing 3D printer, and the variable temperature microfluidic auxiliary printing device is connected to the extruder through the wire, and at the same time, the coolant pipeline is connected to the external cooling system;

[0016] According to the required printing structure and actual needs, select the appropriate printing method, and generate the corresponding path file according to the selected path;

[0017] According to the characteristics of each push tube pushing the wire, set the extruder parameters, and according to the preset shape and diameter of the printing wire, set the corresponding control pressure to adjust the wire output speed;

[0018] During the printing process, the temperature of the printing slurry is monitored by a temperature sensor to ensure that the material is within the appropriate temperature range. According to the actual situation, the flow rate of the coolant is adjusted to maintain the required temperature.

[0019] The printing method includes:

[0020] Parallel movement path: Control the variable temperature microfluidic auxiliary printing device to move in a parallel direction to construct a printed object with rectangular features;

[0021] Rotational movement path: Control the rotation structure so that the printing path will present a pancake shape, which is used to manufacture printed objects with cylindrical features.

[0022] The diameter and shape of the printing filament are monitored in real time during the printing process, and adjustments are made in real time as needed.

[0023] The beneficial effects of the present invention compared to the prior art are as follows: The variable temperature microfluidic assisted printing device and method for FDM 3D printing proposed in the present invention innovatively solve the limitations of traditional FDM 3D printing technology in terms of diversity, temperature control, mixing efficiency and printing path. By dynamically adjusting the temperature, fluidity and mixing ratio of the printing material in real time, the present invention realizes more diversified and efficient printing object manufacturing. The integration of the heater, microfluidic pipeline and coolant pipeline realizes precise temperature control, and different printing materials can be printed at different temperatures. The nozzle of the static mixing structure ensures the uniform mixing of the printing slurry and improves the printing quality and performance. Through the external rotating structure, it is possible to switch between the parallel movement path and the rotational movement path, which improves the flexibility and efficiency of printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings:

[0025] Figure 1 It is a structural schematic diagram of a variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention;

[0026] Figure 2 It is a structural schematic diagram of a push tube of a variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention;

[0027] Figure 3 It is a structural schematic diagram of a microfluidic assisted printing device of the present invention for FDM 3D printing of a variable temperature microfluidic assisted printing device;

[0028] Figure 4 It is a structural schematic diagram of the rotating structure of the variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention;

[0029] Figure 5 A schematic diagram of the nozzle layout of the variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention;

[0030] Figure 6-7 It is a schematic diagram of the static nozzle structure of the variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention;

[0031] Figure 8 It is a schematic diagram of the structure of a mixer with staggered arrangement of special-shaped plates in the nozzle;

[0032] Fig. 9 It is a schematic diagram of printing under a parallel moving path in the FDM 3D printing method of the present invention;

[0033] Fig.10 It is a schematic diagram of printing under a rotational movement path in the FDM 3D printing method of the present invention;

[0034] Fig.11 A physical image obtained by printing by selecting a parallel moving path using the device of the present invention;

[0035] Fig.12 A physical image obtained by printing by selecting a rotational movement path using the device of the present invention;

[0036] In the figure: 001: push tube, 002: microfluidic auxiliary printing device, 003: metal rod, 004: external large gear, 005: microfluidic gear track groove, 006: coolant pipeline, 007: heater, 008: temperature sensor, 009: microfluidic pipeline, 010: nozzle, 011: nozzle, 012: mixer, 013: through hole, 014: connecting joint. DETAILED DESCRIPTION

[0037] like Figures 1 to 12 As shown, the present invention provides a variable temperature microfluidic auxiliary printing device for FDM 3D printing, including a microfluidic auxiliary printing device 002, the microfluidic auxiliary printing device 002 is connected to a rotating structure through external gear meshing, and the microfluidic auxiliary printing device 002 integrates multiple components to achieve temperature, flow and mixing ratio control. The rotating structure is used to control the rotation degree of the microfluidic auxiliary printing device 002 to adapt to different printing requirements.

[0038] The microfluidic auxiliary printing device 002 includes a shell, a plurality of push tubes 001 are arranged on the top of the shell, a plurality of nozzles 010 with a static mixing structure are arranged on the bottom of the shell, a microfluidic device is arranged inside the shell, and the microfluidic device includes a heater 007, a microfluidic pipeline 009, a coolant pipeline 006 and a temperature sensor 008, the heater 007 is arranged in a circle along the inner axis of the shell, the microfluidic pipeline 009 surrounds the heater 007, the coolant pipeline 006 surrounds the microfluidic pipeline 009, each microfluidic pipeline 009 is equipped with a temperature sensor 008, the coolant pipeline 006 is connected to an external cooling system, the feed inlet of the microfluidic pipeline 009 is connected to the discharge port of the push tube 001, and the discharge ports of the plurality of microfluidic pipelines 009 intersect before entering the nozzle 010;

[0039] The controller of the microfluidic device is connected to the control end of the heater, the temperature sensor, and the control end of the external cooling system through wires.

[0040] Among them, the push tube 001 specifically includes three push tubes 001 for pushing different types of printing wires. The push tube 001 is used to adaptively transport wires of different specifications. The upper end is connected to the extruder through the wire, and the lower end is installed at the feed port of the three microfluidic pipelines 009 of the microfluidic auxiliary printing device 002. The push tube 001 is made of stainless steel to avoid wear of the wire. An elastic support structure is provided inside to connect the gears. The function of the elastic support structure is to enable the push tube 001 to adaptively push the thickness of the wire, and to stably fix the wire inside the push tube without horizontal deviation. The gears are set on the inner wall of the push tube 001 and are used to push the wire. See Figure 2 An aerogel gasket is installed at the connection between the lower end of the push tube 001 and the microfluidic auxiliary printing device 002, which effectively isolates the heat conducted upward by the microfluidic auxiliary printing device 002.

[0041] The microfluidic auxiliary printing device 002 is connected to the bottom of the three push tubes 001, and tightly integrates a total of five components, namely, a heater 007, a microfluidic pipeline 009, a coolant pipeline 006, a temperature sensor 008, and an external large gear 004. The heater 007, the microfluidic pipeline 009, the coolant pipeline 006, and the temperature sensor 008 are arranged inside the shell as a microfluidic device, and the external large gear 004 is arranged on the microfluidic gear track groove 005 outside the shell for rotating the shell.

[0042] The integrated heater 007 is located at the inner axis position of the shell of the microfluidic auxiliary printing device 002 and is wrapped by the shell, and is in the shape of a cylinder. Its function is to provide a heat source for the microfluidic auxiliary printing device 002, heat the printing slurry, so as to maintain its appropriate temperature in the microfluidic channel 009 and ensure fluidity. The temperature of the heater 007 can be adjusted according to the requirements of different materials. The lowest temperature of the heater 007 needs to be higher than the highest melting point of the three printing materials to achieve the best fluidity and adhesion, thereby ensuring that each layer of the print has excellent quality and precision.

[0043] The integrated microfluidic pipeline 009 surrounds the heater 007 to transport the heated printing slurry. The three microfluidic pipelines 009 intersect before entering the nozzle 010. The mixing ratio of the three printing slurries is controlled by controlling the speed at which the pushing tube 001 pushes the material.

[0044] The integrated coolant pipe 006 surrounds the microfluidic pipe 009 and maintains the required temperature of the printed slurry by cooling the printed slurry. The coolant pipe 006 is connected to an external cooling system, which is composed of three coolant tanks and a heat sink.

[0045] The microfluidic channels 009 around the heater 007 are used to transport the slurry, and these microfluidic channels 009 are wrapped by the coolant channel 006. In addition, each microfluidic channel 009 is equipped with a temperature sensor 008 for monitoring the temperature of the corresponding slurry and controlling the coolant flow rate to achieve the corresponding temperature adjustment. The integrated temperature sensor 008 is located 2 to 3 mm outside each microfluidic channel 009 and is used to monitor the temperature of the printed slurry in real time. This feedback mechanism helps the external cooling system to accurately adjust the temperature.

[0046] When the coolant temperature is lower than the highest temperature among the three temperature sensors 008, it will not pass through the heat sink, but will directly flow to the coolant tank for heat dissipation. When the coolant temperature is higher than the lowest temperature among the three temperature sensors 008, it will pass through the heat sink and then flow to the coolant tank. The flow rate of the coolant is adjusted according to the feedback information of the temperature sensor 008, so as to accurately adjust the temperature in the microfluidic pipeline of different extruder materials to achieve stable and consistent printing effects.

[0047] The external rotating structure is composed of two metal rods 003 with driving pinions, which are spliced ​​with the external large gear 004 of the shell of the microfluidic assisted printing device 002, wherein the external large gear 004 is arranged in a microfluidic gear track groove 005 opened on the outside of the shell. The external large gear 004 is driven by the pinion through the transmission mechanism so that the microfluidic assisted printing device 002 can rotate during the FDM3D printing process, thereby changing the material stacking method and printing path.

[0048] The bottom of the microfluidic auxiliary printing device 002 is provided with a cross-arranged interface, and a number of nozzles 010 with a static mixing structure are installed. These nozzles 010 are located on the rotation plane of the microfluidic auxiliary printing device 002. Through this layout, each nozzle 010 sets the aperture of the corresponding position through linear interpolation according to the distance d from the rotation center, and can be evenly distributed on the printing surface at different rotation angles to achieve multi-form and multi-angle printing. The nozzle 010 with a static mixing structure ensures that different types of printing slurries are evenly mixed before spraying. This mixing structure ensures that each layer of printing is composed of uniform materials, thereby improving the printing quality and material performance.

[0049] The nozzle 010 of the static mixing structure is composed of a nozzle 011, a mixer 012, a through hole 013, and a connecting joint 014. The nozzle 011 is conical, and a plurality of circular grooves distributed along the axial direction are arranged on the inner wall thereof around the main axis to fix the position of the mixer. The mixers of each layer are interconnected. A connecting joint 014 is arranged on the top of the nozzle 011, and the nozzle 010 is connected to the microfluidic pipeline 009 through the connecting joint 014. The mixer 012 is arranged in the nozzle 011, and is a staggered arrangement of special-shaped plates, such as Figure 7As shown, the through hole 013 is disposed in the mixer 012 to allow the fluid to be divided, reorganized and mixed when passing through so as to generate a rotational motion of the fluid.

[0050] The present invention also proposes an FDM 3D printing method, using the above-mentioned printing device, and the printing steps are as follows:

[0051] The variable temperature microfluidic auxiliary printing device is installed on the existing 3D printer to ensure that the variable temperature microfluidic auxiliary printing device is suitable for the printing platform and compatible with the control system of the 3D printer. The variable temperature microfluidic auxiliary printing device is connected to the extruder through the wire to ensure that the material can be smoothly delivered to the nozzle 010. At the same time, the coolant pipeline 006 is connected to the external cooling system to maintain the appropriate temperature of the variable temperature microfluidic auxiliary printing device and the printing material.

[0052] According to the required printing structure and actual needs, select the appropriate printing method from the parallel movement path and the rotation movement path. According to the selected path, generate the corresponding path file, including the movement coordinates, speed and opening and closing timing of the print head 010. These path files will be used to control the movement of the print head and the extrusion of the material in the subsequent printing process.

[0053] The parallel movement path is: when the variable temperature microfluidic auxiliary printing device moves in the parallel direction, the printing path presents a rectangular parallelepiped shape. In this mode, the print head moves back and forth in the same plane to construct a printed object with rectangular parallelepiped features, such as Fig.11 shown.

[0054] Rotational movement path: By rotating the variable temperature microfluidic assisted printing device, the printing path will present a round shape. Such a printing path is suitable for manufacturing printed objects with cylindrical features, such as Fig.12 shown.

[0055] According to the characteristics of each push tube 001 pushing the wire, set the parameters of the extruder, including extrusion temperature, extrusion speed, etc. According to the preset shape and diameter, set the corresponding control pressure to adjust the wire speed. By accurately controlling the parameters of the extruder, ensure that the diameter and shape of the printing wire are consistent with expectations.

[0056] During the printing process, the temperature of the printing slurry is monitored by the temperature sensor 008 to ensure that the material is within the appropriate temperature range. According to the actual situation, the flow rate of the coolant needs to be adjusted to maintain the required temperature. At the same time, the diameter and shape of the printing filament are monitored and adjusted in real time as needed to ensure printing quality and accuracy.

[0057] The present invention will be further described below based on specific embodiments.

[0058] The variable temperature microfluidic auxiliary printing device for FDM 3D printing of the present invention is installed on an ordinary FDM 3D printer, connected to the extruder through the wire, and the coolant pipeline 006 is connected to the external cooling system;

[0059] Three different types and specifications of filaments are selected as printing materials, namely ABS (diameter 1.75 mm), PLA (diameter 3 mm) and TPU (diameter 1.75 mm), and they are respectively transported to the feed port of the microfluidic auxiliary printing device 002 through the push tube 001;

[0060] According to the performance and requirements of different materials, the pressure of the corresponding extruder is set, and the temperature, flow and mixing ratio are adjusted and controlled through the microfluidic auxiliary printing device 002;

[0061] According to the structure and shape of the printing object, a corresponding printing path is selected and a corresponding path file is generated, and the rotation angle and speed of the microfluidic auxiliary printing device 002 are controlled by the rotating structure, thereby changing the printing path and the material stacking method;

[0062] The mixed printing slurry is sprayed onto the moving platform through the nozzle 010 of the static mixing structure, and is stacked layer by layer to form a printing object.

[0063] In order to verify the effect of the present invention, the present embodiment carries out the following printing experiments with two different shapes and structures:

[0064] Example 1: Printing a rectangular object using a parallel moving path. The object is made of three materials mixed in a ratio of 1:1:1 and has uniform color and performance. The preferred printing parameters are as follows:

[0065] Preset temperature: ABS 230℃, PLA 200℃, TPU 220℃;

[0066] Heater 007 temperature: 250℃;

[0067] Coolant initial flow rate: 0.5L / min;

[0068] Pushing speed of push tube 001: 10mm / s;

[0069] Nozzle 010 diameter: 0.4mm;

[0070] Print layer thickness: 0.2mm;

[0071] Printing speed: 60mm / s;

[0072] - Rotation angle: 0°.

[0073] The experimental results are as follows Fig.11As shown, it can be seen that the printed rectangular object has the characteristics of being smooth, uniform, without gaps, cracks, or deformation, indicating that the present invention can effectively improve the printing quality and accuracy.

[0074] Example 2: Printing a cylindrical object using a rotating moving path. The object is made of three materials mixed in a decreasing ratio of 5:4:3, with gradient colors and properties. The preferred printing parameters are as follows:

[0075] Preset temperature: ABS 230℃, PLA 200℃, TPU 220℃;

[0076] Heater 007 temperature: 250℃;

[0077] Coolant initial flow rate: 0.5L / min;

[0078] Push tube 001 push speed: ABS 10mm / s, PLA 8mm / s, TPU 6mm / s;

[0079] Nozzle 010 diameter: 0.4mm;

[0080] Print layer thickness: 0.2mm;

[0081] Printing speed: 60mm / s;

[0082] Rotation angle: 90°.

[0083] The experimental results are as follows Fig.12 As shown, it can be seen that the printed cylindrical object has the characteristics of smoothness, uniformity, no gaps, no cracks, no deformation, etc., and has changes in color and performance from the inside to the outside, indicating that the present invention can effectively achieve multi-material mixing and gradient printing.

[0084] The printing device and method proposed by the present invention allow the temperature, flow and mixing ratio of the printing material to be adjusted dynamically in real time through the microfluidic auxiliary printing device 002 as needed during the 3D printing process to create a variety of printed objects. The microfluidic auxiliary printing device 002 is provided with a heater 007, and the microfluidic pipeline 009 around the heater 007 is used to transport the slurry, and these pipelines are wrapped by the coolant pipeline 006. In addition, each pipeline is equipped with a temperature sensor 008 for monitoring the temperature of the corresponding slurry and controlling the coolant flow rate to achieve the corresponding temperature adjustment. The microfluidic auxiliary printing device 002 is provided with gears on both sides, and the rotation angle of the microfluidic auxiliary printing device 002 can be controlled by gear transmission. Combined with the multi-nozzle layout and the change of the printing path, the printing of different shapes and structures is realized, and the printing efficiency is improved. The static mixing structure ensures that the printing slurry is evenly mixed, which improves the printing efficiency, printing quality and printing multi-material adaptability. More flexible, efficient and diversified FDM3D printing is achieved, which brings more possibilities for the technical development in the field of FDM3D printing.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A variable temperature microfluidic auxiliary printing device for FDM 3D printing, characterized in that: The invention comprises a microfluidic auxiliary printing device, wherein the microfluidic auxiliary printing device comprises a shell, a plurality of push tubes are arranged on the top of the shell, a plurality of nozzles with a static mixing structure are arranged on the bottom of the shell, a microfluidic device is arranged inside the shell, and the microfluidic device comprises a heater, a microfluidic pipeline, a coolant pipeline and a temperature sensor. The heater is arranged in a circle along the inner axis of the shell, and its function is to provide a heat source for the microfluidic auxiliary printing device, heat the printing slurry, so as to maintain its suitable temperature in the microfluidic pipeline and ensure its fluidity; the microfluidic pipeline surrounds the heater, and the coolant pipeline surrounds the microfluidic pipeline, and the required temperature of the printing slurry is maintained by cooling the printing slurry; each microfluidic pipeline is equipped with a temperature sensor for monitoring the temperature of the corresponding slurry and controlling the flow rate of the coolant to achieve the respective adjustment of the corresponding temperature; the coolant pipeline is connected to an external cooling system, the feed inlet of the microfluidic pipeline is connected to the feed outlet of the push tube, and the feed outlets of multiple microfluidic pipelines intersect before entering the nozzle; The controller of the microfluidic device is connected to the control end of the heater, the temperature sensor, and the control end of the external cooling system through wires; The push tube is made of stainless steel and is provided with an elastic support structure connecting gears. The gears are arranged on the inner wall of the push tube through a connecting rod and are used to push the wire. The mixing ratio of the three printing slurries is controlled by controlling the speed at which the push tube pushes the material. The nozzle comprises a nozzle, a mixer, a through hole and a connecting joint. The nozzle is conical, and a plurality of circular grooves distributed along the axial direction and surrounding the main axis are arranged on the inner wall of the nozzle. The circular grooves are used to fix the position of the mixer. The mixers of each layer are interconnected. A connecting joint is arranged on the top of the nozzle, and the nozzle is connected to the microfluidic pipeline through the connecting joint. The mixer is arranged in the nozzle and is a staggered arrangement structure of special-shaped plates. The through hole is arranged in the mixer, and is used to divide, reorganize and mix the fluid when passing through, so that the fluid produces a rotational motion; The housing is provided with a rotating structure on the outside, the rotating structure comprising two metal rods with driving pinions and a microfluidic gear track groove provided on the outside of the housing, an external large gear is provided in the microfluidic gear track groove, the external large gear is meshed with the driving pinions on the two metal rods, and the driving end of the driving pinion is connected to the controller of the microfluidic device through a wire; The bottom of the shell is provided with a cross-arranged interface, and a nozzle with a static mixing structure is installed on each interface. The nozzle is located on the rotation plane of the microfluidic assisted printing device. The aperture of each nozzle is set at the corresponding position by linear interpolation according to the distance d from the rotation center, and is evenly distributed on the printing surface at different rotation angles, thereby realizing multi-form and multi-angle printing.

2. According to claim 1, a variable temperature microfluidic auxiliary printing device for FDM 3D printing, characterized in that: The external cooling system is composed of a plurality of coolant tanks and a heat dissipation device.

3. The variable temperature microfluidic auxiliary printing device for FDM 3D printing according to claim 1, characterized in that: The temperature sensor is arranged at a distance of 2-3 mm from the microfluidic channel.

4. The variable temperature microfluidic auxiliary printing device for FDM 3D printing according to claim 1, characterized in that: The elastic support structure is arranged on the inner wall of the push tube, and is used to enable the push tube to adapt to the thickness of the push wire and stably fix the wire inside the push tube. An aerogel gasket is installed at the connection between the lower end of the push tube and the microfluidic assisted printing device, and the upper end of the push tube is connected to the extruder through the wire.

5. A variable temperature microfluidic assisted printing method for FDM 3D printing, using the variable temperature microfluidic assisted printing device for FDM 3D printing as described in any one of claims 1 to 4, characterized in that: The steps include: The variable temperature microfluidic auxiliary printing device is installed on the existing 3D printer, and the variable temperature microfluidic auxiliary printing device is connected to the extruder through the wire, and at the same time, the coolant pipeline is connected to the external cooling system; According to the required printing structure and actual needs, select the appropriate printing method, and generate the corresponding path file according to the selected path; According to the characteristics of each push tube pushing the wire, set the extruder parameters, and according to the preset shape and diameter of the printing wire, set the corresponding control pressure to adjust the wire output speed; During the printing process, the temperature of the printing slurry is monitored by a temperature sensor to ensure that the material is within the appropriate temperature range. According to the actual situation, the flow rate of the coolant is adjusted to maintain the required temperature.

6. The variable temperature microfluidic assisted printing method for FDM 3D printing according to claim 5, characterized in that: The printing method includes: Parallel movement path: Control the variable temperature microfluidic auxiliary printing device to move in a parallel direction to construct a printed object with rectangular features; Rotational movement path: Control the rotation structure so that the printing path will present a pancake shape, which is used to manufacture printed objects with cylindrical features.

7. The variable temperature microfluidic assisted printing method for FDM 3D printing according to claim 5, characterized in that: The diameter and shape of the printing filament are monitored in real time during the printing process, and adjustments are made in real time as needed.

Images